JEDDAH, 23 May — Dr. Nadia Ghannam, a leading osteoporosis specialist who operates her own clinic at Badria Towers on Prince Abdullah Street, will give a presentation on osteoporosis at a seminar here today. The event, which will begin at 8.30 p.m. at the Saudi German Hospital auditorium, is organized by the Society for Environment, Agriculture and Technology (SEAT).